EP1339018B1 - Image processing device, image processing method, recording medium and program - Google Patents

Image processing device, image processing method, recording medium and program Download PDF

Info

Publication number
EP1339018B1
EP1339018B1 EP01998179A EP01998179A EP1339018B1 EP 1339018 B1 EP1339018 B1 EP 1339018B1 EP 01998179 A EP01998179 A EP 01998179A EP 01998179 A EP01998179 A EP 01998179A EP 1339018 B1 EP1339018 B1 EP 1339018B1
Authority
EP
European Patent Office
Prior art keywords
image
frequency
converting
frequency components
components
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
EP01998179A
Other languages
German (de)
English (en)
French (fr)
Other versions
EP1339018A1 (en
EP1339018A4 (en
Inventor
Hiroyuki Shinbata
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Canon Inc
Original Assignee
Canon Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Canon Inc filed Critical Canon Inc
Publication of EP1339018A1 publication Critical patent/EP1339018A1/en
Publication of EP1339018A4 publication Critical patent/EP1339018A4/en
Application granted granted Critical
Publication of EP1339018B1 publication Critical patent/EP1339018B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T5/00—Image enhancement or restoration
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
    • H04N1/40—Picture signal circuits
    • H04N1/409—Edge or detail enhancement; Noise or error suppression
    • H04N1/4092—Edge or detail enhancement
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T11/00—2D [Two Dimensional] image generation
    • G06T11/001—Texturing; Colouring; Generation of texture or colour
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T5/00—Image enhancement or restoration
    • G06T5/10—Image enhancement or restoration using non-spatial domain filtering
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T5/00—Image enhancement or restoration
    • G06T5/40—Image enhancement or restoration using histogram techniques
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T5/00—Image enhancement or restoration
    • G06T5/90—Dynamic range modification of images or parts thereof
    • G06T5/92—Dynamic range modification of images or parts thereof based on global image properties
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
    • H04N1/40—Picture signal circuits
    • H04N1/407—Control or modification of tonal gradation or of extreme levels, e.g. background level
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
    • H04N1/40—Picture signal circuits
    • H04N1/407—Control or modification of tonal gradation or of extreme levels, e.g. background level
    • H04N1/4072—Control or modification of tonal gradation or of extreme levels, e.g. background level dependent on the contents of the original
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
    • H04N19/10—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding
    • H04N19/169—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the coding unit, i.e. the structural portion or semantic portion of the video signal being the object or the subject of the adaptive coding
    • H04N19/1883—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the coding unit, i.e. the structural portion or semantic portion of the video signal being the object or the subject of the adaptive coding the unit relating to sub-band structure, e.g. hierarchical level, directional tree, e.g. low-high [LH], high-low [HL], high-high [HH]
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T2207/00—Indexing scheme for image analysis or image enhancement
    • G06T2207/20—Special algorithmic details
    • G06T2207/20048—Transform domain processing
    • G06T2207/20064—Wavelet transform [DWT]
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
    • H04N19/60—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using transform coding
    • H04N19/63—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using transform coding using sub-band based transform, e.g. wavelets

Definitions

  • the present invention relates to an image processing apparatus, image processing method, storage medium, and program and, more particularly, to an image processing apparatus, image processing method, storage medium, and program for changing the dynamic range of image data.
  • an X-ray chest image has a very broad range of pixel values since it is made up of an image region of lungs through which X-rays are readily transmitted, and an image region of a mediastinal part through which X-rays are hardly transmitted. For this reason, it has been considered to be difficult to obtain an X-ray chest image that allows to simultaneously observe both the lungs and mediastinal part.
  • the pixel value (density value) range in which the pixel values of a low-frequency image are equal to or smaller than Dth is compressed.
  • the low-frequency image generation method is different from that in the method given by equation (2).
  • a low-frequency image is generated based on one-dimensional data
  • a low-frequency image is generated based on two-dimensional data.
  • the pixel value (density value) range of the original image the pixel value (density value) range in which the pixel values of a low-frequency image are equal to or smaller than Dth is compressed.
  • Figs. 1 and 2 are views for explaining the principle of that method.
  • the uppermost view in Fig. 1 shows the profile of an edge portion of an original image
  • the middle view shows the profile of a smoothed image of that original image
  • the lowermost view shows the profile of a high-frequency image generated by subtracting the smoothed image from the original image.
  • the uppermost view shows the profile of an image obtained by multiplying by 1/2 the absolute values of the smoothed image in the middle view of Fig. 1
  • the middle view shows the same profile as that of the high-frequency image in Fig.
  • the lowermost view shows the profile of an image obtained by adding the high-frequency image in the interrupt view to the image in the uppermost view obtained by converting the values of the smoothed image.
  • multiple-frequency processes (to be also referred to as multiple-frequency transformation processes hereinafter) using Laplacian pyramid transformation and wavelet transformation have been developed.
  • a frequency process (a process for emphasizing or suppressing specific spatial frequency components) of an image is implemented by converting Laplacian coefficients or wavelet coefficients obtained by decomposing an image into a plurality of frequency components.
  • US 5,644,662 discloses a method of multiple processing a digital representation of a radiographic image that is based on a pyramidal decomposition of said image.
  • a pyramidal decomposition is stored and retrieved to be applied to at least two different processing cycles.
  • an image processing apparatus as set out in claim 1.
  • an image processing apparatus as set out in claim 8.
  • Fig. 3 shows an X-ray photographing apparatus 100 according to the first illustrative example.
  • the X-ray photographing apparatus 100 has a function of executing processes for respective frequency bands of a taken image, and comprises a pre-processing circuit 106, CPU 108, main memory 109, control panel 110, image display 111, and image processing circuit 112, which exchange data via a CPU bus 107.
  • the X-ray photographing apparatus 100 also comprises a data acquisition circuit 105 connected to the pre-processing circuit 106, and a two-dimensional X-ray sensor 104 and X-ray generation circuit 101, which are connected to the data acquisition circuit 105, and these circuits are also connected to the CPU bus 107.
  • the main memory 109 stores various data and the like required for the processing by the CPU 108, and includes a work memory for the CPU 108.
  • the CPU 108 executes operation control and the like of the overall apparatus in accordance with operations at the control panel 110.
  • the X-ray photographing apparatus 100 operates as follows.
  • the X-ray generation circuit 101 emits an X-ray beam 102 toward an object 103 to be examined.
  • the X-ray beam 102 emitted by the X-ray generation circuit 101 is transmitted through the object 103 to be examined while being attenuated, and reaches the two-dimensional X-ray sensor 104.
  • the two-dimensional X-ray sensor 104 detects an X-ray image.
  • the X-ray image is, for example, a human body image or the like in this illustrative example.
  • the data acquisition circuit 105 converts X-ray image information (electrical signal) output from the two-dimensional X-ray sensor 104 into a predetermined electrical signal, and supplies that signal to the pre-processing circuit 106.
  • the pre-processing circuit 106 executes pre-processes such as offset correction, gain correction, and the like for the signal (X-ray image signal) from the data acquisition circuit 105.
  • the X-ray image signal that has undergone the pre-processes by the pre-processing circuit is transferred as an original image to the main memory 109 and image processing circuit 112 via the CPU bus 107 under the control of the CPU 108.
  • Reference numeral 112 denotes a block diagram showing the arrangement of the image processing circuit.
  • reference numeral 113 denotes a tone conversion circuit for performing tone conversion of the original image
  • 114 a discrete wavelet transformation circuit for computing the discrete wavelet transforms (to be referred to as DWTs hereinafter) of the original image that has undergone the tone conversion by the tone conversion circuit 113 to obtain image components (wavelet transform coefficients) of respective frequency bands
  • 115 a component conversion circuit for converting the image components of the respective frequency bands obtained by the discrete wavelet transformation circuit 114
  • an inverse DWT circuit for computing the inverse discrete wavelet transforms (to be referred to as inverse DWTs hereinafter) on the basis of the image components converted by the component conversion circuit 115.
  • Fig. 4 is a flow chart showing the flow of processes in the image processing circuit 112
  • Fig. 5 shows an example of a tone conversion curve used to change the dynamic range of image data by the tone conversion circuit 113
  • Fig. 6A is a circuit diagram showing the arrangement of the DWT circuit 114
  • Fig. 6B shows an example of the format of transform coefficient groups of two levels obtained by a two-dimensional transformation process
  • Fig. 6C is a circuit diagram showing the arrangement of the inverse DWT circuit 116.
  • Figs. 7 and 8 show examples of function forms used to change image components (DWT coefficients).
  • An original image that has undergone the pre-processes in the pre-processing circuit 106 is transferred to the image processing circuit 112 via the CPU bus 107.
  • the tone conversion circuit converts an original image Org(x, y) into f(Org(x, y) using a tone conversion curve f() (s201).
  • a "curve” may be used synonymously with a "function”.
  • x and y are the coordinates on the original image.
  • the tone conversion curve f() for example, a curve form shown in Fig. 5 is used.
  • Broken line 2 indicates a function form for compressing the dynamic range on the low pixel value side
  • broken line 3 indicates a function form for expanding the dynamic range on the low pixel value side
  • broken line 4 expands the dynamic range on the high pixel value side
  • broken line 5 indicates a function form for compressing the dynamic range on the high pixel value side.
  • these curve forms are preferably formed to be differential continuous (differentiable and continuous functions). This is because a false edge may be generated when the tone conversion curve includes an undifferentiable or discontinuous point.
  • the DWT circuit (discrete wavelet transformation circuit) 114 executes a two-dimensional discrete wavelet transformation process of the image f(Org(x, y) after tone conversion, and calculates and outputs image components (to be also referred to as transform coefficients or frequency coefficients hereinafter).
  • the image data stored in the main memory 109 is sequentially read out and undergoes the transformation process by the DWT circuit 114, and is written in the main memory 109 again.
  • an input image signal is separated into odd and even address signals by a combination of a delay element and down samplers, and undergoes filter processes of two filters p and u.
  • a linear discrete wavelet transformation process is done for an image signal. Since two-dimensional discrete wavelet transformation is implemented by sequentially executing linear discrete wavelet transformation in the horizontal and vertical directions of an image and its details are known to those who are skilled in the art, a description thereof will be omitted.
  • Fig. 6B shows an example of the format of transform coefficient groups of two levels obtained by the two-dimensional discrete wavelet transformation process.
  • An image signal is decomposed into image components HH1, HL1, LH1,..., LL in different frequency bands (s202).
  • each of HH1, HL1, LH1,..., LL (to be referred to as subbands hereinafter) indicates an image component for each frequency band.
  • image components after the tone conversion process which become f'() times (f'() is the slope of the tone conversion curve f() in Org(x, y) corresponding to hn(x, y)) those of the original image Org(x, y) by the tone conversion process, can be converted into values nearly equal to those of the original image Org(x, y).
  • the image components of the LL subband as the low-frequency component of the lowermost layer are not changed.
  • the dynamic range of the overall image is changed, but image components corresponding to high-frequency components can maintain values nearly equal to those of the original image.
  • the right-hand side of equation (13) may be multiplied by a predetermined constant. In this case, the high-frequency components of an image can be adjusted (emphasized or suppressed) while changing the dynamic range.
  • equation (13) may be multiplied by a predetermined function having a curve form which depends on the pixel values of the original image Org(x, y) or its smoothed image.
  • a predetermined function having a curve form which depends on the pixel values of the original image Org(x, y) or its smoothed image.
  • Such function has a curve form that assumes a small value when the pixel value of the original image Org(x, y) or its smoothed image is equal to or lower than a predetermined pixel value, or assumes a large value when the pixel value is higher than the predetermined pixel value.
  • the absolute values of high-frequency components in a low pixel value region can be suppressed, and noise components can be made less conspicuous.
  • the image does not suffer any artifacts such as overshoot and the like.
  • the process given by equation (13) can amplify high-frequency components by changing them, but artifacts such as overshoot and the like may be generated.
  • the function fn() has a curve form shown in Fig. 7 or 8 .
  • the abscissa plots the input coefficients
  • the ordinate plots the output coefficients.
  • Figs. 7 and 8 show conversion curves when the frequency coefficients are +, and the same conversion is made even when the frequency coefficients are -. That is, Figs. 7 and 8 show only the first quadrant of an odd function.
  • all functions used to convert frequency coefficients are odd functions, and only their first quadrants are shown. These curves are differential continuous (differentiable and continuous functions), and can prevent generation of any false edges.
  • Image components generated at an edge have values larger than normal components, and these curve forms set image components corresponding to edge components to be 0 or suppress them.
  • equation (14) when an image component is large, fn(hn(x, y)) becomes 0 or a suppressed value, and h2n(x, y) becomes nearly equal to hn(x, y) or a suppressed value (a value smaller than an image component of the original image).
  • h2n(x, y) when an image component has a normal value, h2n(x, y) given by equation (14) becomes the same value as equation (13).
  • the dynamic range is changed, and effective image components (those equal to or lower than the predetermined value) of the high-frequency components become equal to those of the image before tone conversion. Since image components (those higher than the predetermined value) that cause overshoot of the high-frequency components are not added, i.e., changed, or are added or changed while being suppressed, overshoot or the like can be prevented or suppressed.
  • the slope of the function form fn() to be equal to or larger than 1 (or larger than 1) within the range where the input value is equal to or smaller than the predetermined value, high-frequency components can be emphasized while suppressing overshoot.
  • the dynamic range and high-frequency components can be simultaneously changed while suppressing overshoot and the like.
  • the inverse DWT circuit 116 computes the inverse discrete wavelet transforms of image components (transform coefficients) converted by the component conversion circuit 115 as follows (s204).
  • the converted image components stored in the main memory 109 are sequentially read out and undergo the inverse transformation process by the inverse discrete wavelet transformation circuit 116, and are written in the main memory 109 again.
  • the arrangement of the inverse discrete wavelet transformation of the inverse DWT circuit 116 in this embodiment is as shown in Fig. 6C .
  • Input image components undergo filter processes using two filters u and p, and are added to each other after being up-sampled, thus outputting an image signal x'.
  • the dynamic range change process is implemented by exploiting the multiple-frequency transformation process, and high-frequency components are adjusted in correspondence with tone conversion used to change the dynamic range, a high-quality output image, the dynamic range of which has been changed, can be obtained. Also, the dynamic range of an image can be changed, and high-frequency components can be changed at the same time, while suppressing artifacts such as overshoot and the like. In this manner, a dynamic range change process such as dynamic range compression or the like and a sharpening process for each frequency band by changing frequency components for each frequency band can be simultaneously executed.
  • the second illustrative example will be described below along with the flow of processes shown in Fig. 9 . A description of the same processes as those in first illustrative example will be omitted.
  • the DWT circuit 114 executes a DWT process of an original image Org(x, y). Let horgn(x, y) be each image component obtained by that process (s601).
  • the tone conversion circuit 113 executes a tone conversion process of the original image Org(x, y) using a tone conversion curve f() (s602).
  • the DWT circuit 114 executes a DWT process of the image f(Org(x, y)) that has undergone the tone conversion process to obtain image components hn(x, y) (s603).
  • n indicates the subband category and x and y are the coordinates as in the first illustrative example.
  • the image components of the LL subband as the low-frequency component of the lowermost layer are not changed.
  • the magnitudes of high-frequency components of the image, the dynamic range of which has been changed can be maintained to be nearly equal to those of high-frequency components of the original image.
  • the magnitudes of the high-frequency components can accurately come closer to those of the high-frequency components of the original image.
  • the second term of the right-hand side of equation (17) may be multiplied by a predetermined constant. In this case, the high-frequency components of the image can be adjusted (emphasized or suppressed) while changing the dynamic range.
  • equation (17) may be multiplied by a predetermined function having a curve form which depends on the pixel values of the original image Org(x, y) or its smoothed image.
  • a predetermined function having a curve form which depends on the pixel values of the original image Org(x, y) or its smoothed image.
  • Such function has a curve form that assumes a small value when the pixel value of the original image Org(x, y) or its smoothed image is equal to or lower than a predetermined pixel value, or assumes a large value when the pixel value is higher than the predetermined pixel value.
  • the image does not suffer any artifacts such as overshoot and the like.
  • the process given by equation (17) can amplify high-frequency components by adding those of the original image, but simultaneously adds components of the original image which may cause artifacts such as overshoot and the like. Hence, overshoot may occur.
  • the function fn() has a curve form shown in Fig. 7 or 8 .
  • Image components generated at an edge have values larger than normal components, and these curve forms set image components corresponding to edge components to 0 or suppress them.
  • fn(horgn(x, y)) becomes 0 or a suppressed value
  • h2n(x, y) becomes nearly equal to hn(x, y) or a suppressed value smaller than horgn(x, y).
  • h2n(x, y) becomes the same value as equation (17)
  • the inverse DWT circuit 116 executes an inverse DWT process based on the image components changed by the component change circuit 115 (S605).
  • the dynamic range change process is implemented by exploiting the multiple-frequency process, and high-frequency components are adjusted in correspondence with tone conversion used to change the dynamic range, a high-quality image, the dynamic range of which has been changed, can be obtained. Furthermore, since high-frequency components of the original image are used as those to be added, high-frequency components of the processed image can accurately come closer to those of the original image. Also, the dynamic range and high-frequency components can be changed at the same time while suppressing artifacts such as overshoot and the like. In this manner, a dynamic range change process such as dynamic range compression or the like and a sharpening process for each frequency band by changing frequency components for each frequency band can be simultaneously executed to obtain a high-quality output image.
  • a dynamic range change process such as dynamic range compression or the like and a sharpening process for each frequency band by changing frequency components for each frequency band can be simultaneously executed to obtain a high-quality output image.
  • the tone conversion circuit 113 executes a tone conversion process of an original image Org(x, y) using a tone conversion curve f() to obtain a processed image f(Org(x, y) (s701).
  • the DWT circuit 114 then executes a DWT process of the original image to obtain image components hn(x, y) (s702).
  • n indicates the subband category and x and y are the coordinates as in the first illustrative example.
  • the values of the lowest frequency component LL are set to be all 0s (zeros).
  • equation (20) may be multiplied by a predetermined function having a curve form which depends on the pixel values of the original image Org(x, y) or its smoothed image.
  • a predetermined function having a curve form which depends on the pixel values of the original image Org(x, y) or its smoothed image.
  • Such function has a curve form that assumes a small value when the pixel value of the original image Org(x, y) or its smoothed image is equal to or lower than a predetermined pixel value, or assumes a large value when the pixel value is higher than the predetermined pixel value.
  • the inverse DWT circuit 116 computes the inverse DWTs based on the components converted by the component conversion circuit 115 to obtain a restored image Hr(x, y) (s704).
  • the image does not suffer any artifacts such as overshoot and the like.
  • the high-frequency components obtained by equation (20) contain components of the original image which may cause artifacts such as overshoot and the like. Therefore, an image obtained by inversely transforming such image components contains components which may cause overshoot, and if that image is added, overshoot may occur.
  • the function fn() has a curve form shown in Fig. 7 or 8 .
  • image components high-frequency components
  • these curve forms set image components corresponding to edge components to 0 or suppress them.
  • fn(hn(x, y)) becomes 0 or a suppressed value
  • h2n(x, y) also becomes 0 or a suppressed value.
  • h2n(x, y) becomes the same value as equation (20).
  • the dynamic range change process is implemented by exploiting the multiple-frequency process, and high-frequency components are adjusted in correspondence with tone conversion used to change the dynamic range, a high-quality image, the dynamic range of which has been changed, can be obtained. Furthermore, since high-frequency components of the original image are used as those to be added, high-frequency components of the processed image can accurately come closer to those of the original image. Also, since the DWT process need be done only once, the computation time can be shortened. Moreover, the dynamic range and high-frequency components can be changed at the same time while suppressing artifacts such as overshoot and the like. In this manner, a dynamic range change process such as dynamic range compression or the like and a sharpening process for each frequency band by changing frequency components for each frequency band can be simultaneously executed to obtain a high-quality output image.
  • a dynamic range change process such as dynamic range compression or the like and a sharpening process for each frequency band by changing frequency components for each frequency band can be simultaneously executed to obtain a high-quality output image.
  • the third illustrative example relates to an image process for obtaining the effects of the dynamic range change and frequency processes while preserving the edge structure.
  • Fig. 11 is a block diagram showing the arrangement of the third illustrative example, and a description of the same processes as in the first illustrative example will be omitted.
  • reference numeral 112 denotes an image processing circuit
  • 2101 a frequency band decomposing circuit for decomposing an original image into a plurality of frequency bands by wavelet transformation, Laplacian pyramid transformation, or the like to obtain frequency coefficients
  • 2102 a coefficient conversion circuit for converting the coefficients on the basis of the slope of a tone conversion curve used later to change the dynamic range
  • 2103 an inverse conversion circuit for inversely converting the coefficients obtained by conversion by the coefficient conversion circuit 2102
  • 2104 a tone conversion circuit for changing the dynamic range of the image, obtained by inverse conversion by the inverse conversion circuit 2103.
  • Fig. 12 is a flow chart showing the flow of processes of the image processing circuit 112 according to the third illustrative example.
  • Fig. 13 shows an example of the coefficient conversion curve used in the coefficient conversion circuit 2102. In Fig. 13 , the abscissa plots input coefficients, and the ordinate plots output coefficients.
  • the frequency band decomposing circuit 2101 executes a two-dimensional discrete wavelet transformation process of an original image f(x, y), and outputs frequency coefficients (s2201).
  • the frequency coefficient decomposing method may be any method of wavelet transformation, Laplacian pyramid transformation, and the like.
  • the image is decomposed into frequency coefficients HH1, HL1, LH1,..., LL for respective frequency bands using two-dimensional discrete wavelet transformation.
  • the coefficient conversion circuit 2102 converts the frequency coefficients in accordance with a tone conversion curve (e.g., a conversion curve shown in Fig. 5 ) F() used in the tone conversion circuit 2104 (s2202).
  • a tone conversion curve e.g., a conversion curve shown in Fig. 5
  • F() used in the tone conversion circuit 2104 (s2202).
  • a predetermined absolute value e.g., a predetermined absolute value
  • This predetermined absolute value is determined by experiments depending on the magnitudes of coefficients with respect to the edge of an image.
  • the edge structure can be preserved when coefficients higher than the predetermined absolute value remain unchanged, and artifacts such as overshoot and the like can be suppressed in a reconstructed image.
  • hn(x, y) are frequency coefficients of n levels, i.e., coefficients of a region 2301 equal to or lower than a predetermined absolute value
  • the function f5() has a curve form which depends on the pixel values of the original image f(x, y) or its smoothed image, for example, a curve form that assumes a small value when the pixel value of the original image f(x, y) or its smoothed image is equal to or lower than a predetermined pixel value, or assumes a large value when the pixel value is higher than the predetermined pixel value.
  • a conversion curve F2() in Fig. 13 expresses the above process, and the coefficients of the region 2301 are not always linearly converted but are converted based on equation (23).
  • the inverse conversion circuit 2103 inversely converts h2n(x, y) (inverse DWT) (S2203). A restored image f2(x, y) is then obtained.
  • the frequency coefficients are changed in advance on the basis of a curve form of tone conversion used to change the dynamic range, the magnitudes of high-frequency components in an image, the dynamic range of which has been changed, can be maintained nearly equal to those of high-frequency components of the original image. Since coefficient values within the predetermined absolute value range are not changed, the edge structure can be preserved, and overshoot and the like can be suppressed even in an image which has undergone the frequency process and dynamic range change process.
  • the conversion function F2() has an undifferentiable and discontinuous point, but no artifacts such as false edges or the like appear in the inversely converted image. This is because no structure which is visually recognized as a continuous boundary such as a line or the like appears on the inversely converted image since coefficients having the predetermined absolute value (those corresponding to the undifferentiable and discontinuous point of the conversion curve) are randomly distributed in the coefficient domain. That is, the wavelet coefficients are frequency coefficients, and a predetermined image domain is restored by the inverse wavelet transformation process in correspondence with the magnitudes of frequency components. Note that frequency coefficients of the predetermined absolute value may often be arranged continuously in correspondence with the edge portion of an image in the coefficient domain. In such case, since a continuous structure in the coefficient domain, which appears after coefficient conversion using a discontinuous function like the conversion function F2(), appears as a continuous structure along the edge portion even on the restored image, it is not recognized as a false edge.
  • a.noise suppression process a sharpening process, or a hybrid process with other processes can be easily done.
  • an analysis process or the like based on coefficients upon decomposing the original image into multiple-frequency coefficients is done, and predetermined frequency coefficients are converted based on the analysis result or the like.
  • the scope of the present invention includes a case wherein the functions of the embodiment are implemented by supplying a program code of software that implements the functions of the embodiments to a computer (or a CPU or MPU) in an apparatus or system connected to various devices, and making the computer in the system or apparatus operate the various devices in accordance with the stored program, so as to operate the various devices for the purpose of implementing the functions of the embodiment.
  • the program code itself read out from the storage medium implements the functions of the embodiment, and the program code itself, and means for supplying the program code to the computer (i.e., a storage medium which stores the program code) constitutes the present invention.
  • a floppy disk, hard disk, optical disk, magneto-optical disk, CD-ROM, magnetic tape, nonvolatile memory card, ROM, and the like may be used as the storage medium for storing such program code.
  • a floppy disk, hard disk, optical disk, magneto-optical disk, CD-ROM, magnetic tape, nonvolatile memory card, ROM, and the like may be used as the storage medium for storing such program code.
  • the program code also constitutes the present invention not only when the functions of the embodiment are implemented by executing the supplied program code by the computer but also when the functions of the embodiment are implemented by collaboration of the program code and an OS (operating system) or another application software running on the computer.
  • OS operating system
  • program code constitutes the present invention when the functions of the embodiment are implemented by some or all of actual processes executed by a CPU or the like arranged in a function extension board or a function extension unit, which is inserted in or connected to the computer, after the supplied program code is written in a memory of the extension board or unit.
  • tone conversion and conversion of frequency components based on it are made using the tone conversion process and multiple-frequency transformation process, a high-quality output image can be obtained.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Theoretical Computer Science (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • Image Processing (AREA)
  • Ultra Sonic Daignosis Equipment (AREA)
  • Processing Or Creating Images (AREA)
EP01998179A 2000-11-30 2001-11-28 Image processing device, image processing method, recording medium and program Expired - Lifetime EP1339018B1 (en)

Applications Claiming Priority (5)

Application Number Priority Date Filing Date Title
JP2000365328 2000-11-30
JP2000365328 2000-11-30
JP2001105846 2001-04-04
JP2001105846 2001-04-04
PCT/JP2001/010387 WO2002045019A1 (en) 2000-11-30 2001-11-28 Image processing device, image processing method, recording medium and program

Publications (3)

Publication Number Publication Date
EP1339018A1 EP1339018A1 (en) 2003-08-27
EP1339018A4 EP1339018A4 (en) 2005-11-16
EP1339018B1 true EP1339018B1 (en) 2008-12-17

Family

ID=26604965

Family Applications (1)

Application Number Title Priority Date Filing Date
EP01998179A Expired - Lifetime EP1339018B1 (en) 2000-11-30 2001-11-28 Image processing device, image processing method, recording medium and program

Country Status (9)

Country Link
US (3) US7076111B2 (ja)
EP (1) EP1339018B1 (ja)
JP (1) JP3796480B2 (ja)
KR (1) KR100547330B1 (ja)
CN (1) CN1291354C (ja)
AT (1) ATE418122T1 (ja)
CA (1) CA2427529C (ja)
DE (1) DE60137076D1 (ja)
WO (1) WO2002045019A1 (ja)

Families Citing this family (24)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3833177B2 (ja) * 2000-11-30 2006-10-11 キヤノン株式会社 画像処理装置、画象処理方法、記憶媒体及びプログラム
JP3754933B2 (ja) * 2001-06-19 2006-03-15 キヤノン株式会社 画像処理装置、画像処理システム、画像処理方法、プログラム及び記憶媒体
US7315656B2 (en) * 2003-05-22 2008-01-01 The Boeing Company Methods and apparatus for enhanced viewing of aerial refueling operations
JP3870173B2 (ja) * 2003-06-11 2007-01-17 キヤノン株式会社 画像処理方法、画像処理装置、プログラム及びコンピュータ記録媒体
JP4500539B2 (ja) * 2003-12-26 2010-07-14 キヤノン株式会社 画像処理装置、画像処理方法、プログラム及び記憶媒体
US8594448B2 (en) * 2004-08-16 2013-11-26 Hewlett-Packard Development Company, L.P. Bi-selective filtering in transform domain
EP1777938A1 (en) * 2005-10-19 2007-04-25 Thomson Licensing Method, system and device for colour quality control
WO2007046219A1 (ja) * 2005-10-19 2007-04-26 Konica Minolta Holdings, Inc. 画像処理装置及び画像処理方法
WO2008111236A1 (en) * 2007-03-14 2008-09-18 Olympus Corporation Image processing system and image processing program
US20080275736A1 (en) * 2007-05-04 2008-11-06 Siemens Medical Solutions Usa, Inc. System of Picture Archiving and Communication System With Message Broadcasting Mechanism
US8566119B2 (en) * 2007-05-04 2013-10-22 Siemens Medical Solutions Usa, Inc. Method of Picture Archiving Communication System messaging intelligent update mechanism
US20080275734A1 (en) * 2007-05-04 2008-11-06 Siemens Medical Solutions Usa, Inc. Method and Apparatus for Picture Archiving Communication System With STAT Workflow
JP4860551B2 (ja) * 2007-06-01 2012-01-25 株式会社キーエンス 拡大観察装置、高階調画像ファイル作成方法、高階調画像ファイル作成方法、高階調画像ファイル作成プログラム及びコンピュータで読み取り可能な記録媒体
JP5331797B2 (ja) * 2008-04-14 2013-10-30 株式会社日立メディコ 医用診断装置および医用診断装置の画質改善方法
US8363131B2 (en) * 2009-01-15 2013-01-29 Aptina Imaging Corporation Apparatus and method for local contrast enhanced tone mapping
CN101477683B (zh) * 2009-01-20 2011-07-20 深圳市蓝韵实业有限公司 一种自适应超声图像灰阶映射方法
JP5235759B2 (ja) * 2009-04-07 2013-07-10 キヤノン株式会社 画像処理装置、画像処理方法、及びプログラム
WO2011040074A1 (ja) * 2009-09-30 2011-04-07 シャープ株式会社 画像拡大装置、画像拡大プログラム、及び表示装置
JP5365578B2 (ja) 2010-05-14 2013-12-11 株式会社島津製作所 画像処理方法およびそれを用いた放射線撮影装置
CN105488765B (zh) * 2015-11-23 2018-12-07 沈阳东软医疗系统有限公司 一种图像动态范围调整方法及装置
WO2017219962A1 (en) * 2016-06-21 2017-12-28 Zhejiang Dahua Technology Co., Ltd. Systems and methods for image processing
CN106637981B (zh) * 2016-12-06 2019-05-07 苏州晟德竹科技发展有限公司 可提高纤维丝织造效率的油剂乳液和方法
JP6926856B2 (ja) * 2017-09-07 2021-08-25 コニカミノルタ株式会社 放射線画像処理装置、プログラム及び放射線画像処理方法
JP7226463B2 (ja) 2021-02-04 2023-02-21 コニカミノルタ株式会社 画像処理装置、放射線画像撮影システム及び制御プログラム

Family Cites Families (35)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS58182957A (ja) 1982-04-20 1983-10-26 Fuji Photo Film Co Ltd 画像の鮮鋭度強調方式
US4618990A (en) * 1984-11-15 1986-10-21 General Electric Company Edge enhancement filtering for digital fluorography images
DE3629409C2 (de) 1986-08-29 1994-02-17 Agfa Gevaert Ag Verfahren und Vorrichtung zur Kontrastbewertung bei der elektronischen Bildverarbeitung
US5253082A (en) * 1988-03-10 1993-10-12 Canon Kabushiki Kaisha Image forming apparatus
US5012096A (en) * 1989-05-20 1991-04-30 Fujitsu Limited Digital X-ray apparatus
JP2663189B2 (ja) 1990-01-29 1997-10-15 富士写真フイルム株式会社 画像のダイナミックレンジ圧縮処理方法
JP2574923B2 (ja) 1990-04-10 1997-01-22 大日本スクリーン製造株式会社 輪郭強調方法および画像処理装置
JP3114208B2 (ja) 1991-01-08 2000-12-04 日本電気株式会社 適応画像強調回路
JPH04284066A (ja) 1991-03-13 1992-10-08 Mitsubishi Electric Corp ビデオプリンタ
DE69214229T2 (de) * 1991-08-14 1997-04-30 Agfa Gevaert Nv Verfahren und Vorrichtung zur Kontrastverbesserung von Bildern
JP2509503B2 (ja) 1992-09-11 1996-06-19 コニカ株式会社 画像処理方法及び装置
EP0610604A1 (en) * 1993-02-11 1994-08-17 Agfa-Gevaert N.V. Multiple processing of radiographic images based on a pyramidal image decomposition
JP3205417B2 (ja) * 1993-03-18 2001-09-04 富士写真フイルム株式会社 画像処理方法
JPH06274614A (ja) * 1993-03-18 1994-09-30 Fuji Photo Film Co Ltd 画像処理方法
US6009208A (en) * 1995-08-21 1999-12-28 Lucent Technologies Inc. System and method for processing space-time images
JPH0991423A (ja) 1995-09-28 1997-04-04 Fuji Photo Film Co Ltd 画像処理方法および装置
KR100206319B1 (ko) 1995-12-13 1999-07-01 윤종용 비디오 신호의 로컬 콘트라스트 개선을 위한 방법및장치
JPH09212623A (ja) * 1996-01-30 1997-08-15 Fuji Photo Film Co Ltd 画像処理方法
US5799112A (en) 1996-08-30 1998-08-25 Xerox Corporation Method and apparatus for wavelet-based universal halftone image unscreening
JPH10164469A (ja) 1996-11-29 1998-06-19 Sony Corp 画像強調装置、画像強調方法およびビデオプリンター
JP3700804B2 (ja) * 1996-12-13 2005-09-28 富士写真フイルム株式会社 画像処理方法および装置
JPH10302052A (ja) * 1997-04-23 1998-11-13 Ricoh Co Ltd 画像処理方式
JP3213582B2 (ja) 1997-05-29 2001-10-02 シャープ株式会社 画像符号化装置及び画像復号装置
JP3746596B2 (ja) * 1997-07-23 2006-02-15 株式会社リコー 画像処理装置
JPH1166280A (ja) * 1997-08-25 1999-03-09 Shimadzu Corp 医用画像処理装置
JP3781883B2 (ja) * 1997-12-11 2006-05-31 株式会社リコー 画像処理装置
JP3631609B2 (ja) * 1998-03-20 2005-03-23 株式会社リコー 画像処理装置、画像処理方法
JPH11355575A (ja) * 1998-04-09 1999-12-24 Ricoh Co Ltd 画像処理装置
US7050648B1 (en) 1998-09-18 2006-05-23 Canon Kabushiki Kaisha Image processing apparatus, image processing method, and recording medium
DE19849090A1 (de) * 1998-10-24 2000-04-27 Philips Corp Intellectual Pty Verfahren zur Verarbeitung eines Eingangsbildes
US6167165A (en) 1998-11-25 2000-12-26 Eastman Kodak Company Method for adjusting image detail to compensate for an applied tone scale
JP4244094B2 (ja) * 1999-02-17 2009-03-25 富士フイルム株式会社 画像処理方法および装置並びに記録媒体
JP3733260B2 (ja) 1999-04-30 2006-01-11 キヤノン株式会社 画像処理装置及び画像処理方法
JP3833177B2 (ja) 2000-11-30 2006-10-11 キヤノン株式会社 画像処理装置、画象処理方法、記憶媒体及びプログラム
JP3754933B2 (ja) 2001-06-19 2006-03-15 キヤノン株式会社 画像処理装置、画像処理システム、画像処理方法、プログラム及び記憶媒体

Also Published As

Publication number Publication date
EP1339018A1 (en) 2003-08-27
CN1478250A (zh) 2004-02-25
JP3796480B2 (ja) 2006-07-12
ATE418122T1 (de) 2009-01-15
US7248748B2 (en) 2007-07-24
US20020159623A1 (en) 2002-10-31
WO2002045019A1 (en) 2002-06-06
KR100547330B1 (ko) 2006-01-26
CA2427529A1 (en) 2002-06-06
US7447376B2 (en) 2008-11-04
CA2427529C (en) 2009-04-28
EP1339018A4 (en) 2005-11-16
CN1291354C (zh) 2006-12-20
KR20030066688A (ko) 2003-08-09
JPWO2002045019A1 (ja) 2004-04-02
US20070188785A1 (en) 2007-08-16
DE60137076D1 (de) 2009-01-29
US7076111B2 (en) 2006-07-11
US20060110061A1 (en) 2006-05-25

Similar Documents

Publication Publication Date Title
EP1339018B1 (en) Image processing device, image processing method, recording medium and program
EP1341123B1 (en) Image processing device, image processing method, storage medium, and program
US6813335B2 (en) Image processing apparatus, image processing system, image processing method, program, and storage medium
US7627169B2 (en) Image processing apparatus and method
US7024036B2 (en) Image processing apparatus, image processing method, storage medium, and program
EP1526479B1 (en) Image noise attenuation
JP3814421B2 (ja) 画像処理装置、方法及びコンピュータ読み取り可能な記憶媒体
JP2003337942A (ja) 画像処理装置
JP4818212B2 (ja) 画像処理装置及び方法
JP2004173078A (ja) 画像処理装置

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20030527

AK Designated contracting states

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR

AX Request for extension of the european patent

Extension state: AL LT LV MK RO SI

A4 Supplementary search report drawn up and despatched

Effective date: 20050929

17Q First examination report despatched

Effective date: 20070627

GRAP Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOSNIGR1

GRAS Grant fee paid

Free format text: ORIGINAL CODE: EPIDOSNIGR3

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR

REG Reference to a national code

Ref country code: GB

Ref legal event code: FG4D

REG Reference to a national code

Ref country code: CH

Ref legal event code: EP

REG Reference to a national code

Ref country code: IE

Ref legal event code: FG4D

REF Corresponds to:

Ref document number: 60137076

Country of ref document: DE

Date of ref document: 20090129

Kind code of ref document: P

REG Reference to a national code

Ref country code: SE

Ref legal event code: TRGR

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: ES

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20090328

Ref country code: BE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20081217

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: PT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20090518

Ref country code: AT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20081217

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20081217

26N No opposition filed

Effective date: 20090918

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: MC

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20091130

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20091128

Ref country code: LI

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20091130

Ref country code: CH

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20091130

Ref country code: GR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20090318

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LU

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20091128

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: TR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20081217

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: CY

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20081217

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FI

Payment date: 20141105

Year of fee payment: 14

Ref country code: SE

Payment date: 20141124

Year of fee payment: 14

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 20141126

Year of fee payment: 14

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: IT

Payment date: 20141110

Year of fee payment: 14

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20151128

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

Effective date: 20160729

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20151129

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20151130

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FI

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20151128

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: NL

Payment date: 20201126

Year of fee payment: 20

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 20201126

Year of fee payment: 20

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20201228

Year of fee payment: 20

REG Reference to a national code

Ref country code: DE

Ref legal event code: R071

Ref document number: 60137076

Country of ref document: DE

REG Reference to a national code

Ref country code: NL

Ref legal event code: MK

Effective date: 20211127

REG Reference to a national code

Ref country code: GB

Ref legal event code: PE20

Expiry date: 20211127

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF EXPIRATION OF PROTECTION

Effective date: 20211127